Sensor and monitor system

ABSTRACT

A monitor system is disclosed. The monitor system includes a sensor with a sensor port. The monitor system further includes a recorder with a recorder port within a recording housing. The recorder port interfaces with the sensor port to receive signals from the sensor port. A recorder clock is defined within the recorder housing, with a recorder processor to store signals from the sensor. The recorder includes a data port to interface with a dock receiver. The monitor system includes a dock remotely located from the sensor and the recorder. The dock receiver couples the recorder to the dock. The monitor system further includes a data processor to analyze the sensor signals from the recorder. The data processor includes memory and a clock. Further included with the data processor are program instructions to assign the time and date of the sensor signals.

FIELD OF THE INVENTION

This invention relates to monitor systems and, in particularembodiments, to devices and methods for monitoring of an sensor todetermine a characteristic of a body.

BACKGROUND OF THE INVENTION

Over the years, bodily characteristics have been determined by obtaininga sample of bodily fluid. For example, diabetics often test for bloodglucose levels. Traditional blood glucose determinations have utilized apainful finger prick using a lancet to withdraw a small blood sample.This results in discomfort from the lancet as it contacts nerves in thesubcutaneous tissue. The pain of lancing and the cumulative discomfortfrom multiple needle pricks is a strong reason why patients fail tocomply with a medical testing regimen used to determine a change incharacteristic over a period of time. Although non-invasive systems havebeen proposed, or are in development, none to date have beencommercialized that are effective and provide accurate results. Inaddition, all of these systems are designed to provide data at discretepoints and do not provide continuous data to show the variations in thecharacteristic between testing times.

A variety of implantable electrochemical sensors have been developed fordetecting and/or quantifying specific agents or compositions in apatient's blood. For instance, glucose sensors have been developed foruse in obtaining an indication of blood glucose levels in a diabeticpatient. Such readings are useful in monitoring and/or adjusting atreatment regimen which typically includes the regular administration ofinsulin to the patient. Thus, blood glucose readings improve medicaltherapies with semi-automated medication infusion pumps of the externaltype, as generally described in U.S. Pat. Nos. 4,562,751; 4,678,408; and4,685,903; or automated implantable medication infusion pumps, asgenerally described in U.S. Pat. No. 4,573,994, which are hereinincorporated by reference. Typical thin film sensors are described incommonly assigned U.S. Pat. Nos. 5,390,671; 5,391,250; 5,482,473; and5,586,553 which are incorporated by reference herein, also see U.S. Pat.No. 5,299,571. However, the monitors for these continuous sensorsprovide alarms, updates, trend information and require sophisticatedhardware to allow the user to program the monitor, calibrate the sensor,enter data and view data in the monitor and to provide real-timefeedback to the user. This sophisticated hardware makes it mostpractical for users that require continuous monitoring with feedback tomaintain tight control over their conditions. In addition, these systemsrequire the user to be trained in their use, even if to be worn forshort periods of time to collect medical data which will be analyzedlater by a doctor.

Doctors often need continuous measurements of a body parameter over aperiod of time to make an accurate diagnosis of a condition. Forinstance, Holter monitor systems are used to measure the EKG of apatient's heart over a period of time to detect abnormalities in theheart beat of the patient. Abnormalities detected in this manner maydetect heart disease that would otherwise go undetected. These tests,while very useful are limited to monitoring of bio-mechanical physicalchanges in the body, such as a heart beat, respiration rate, bloodpressure or the like.

SUMMARY OF THE DISCLOSURE

A monitor system to monitor a characteristic of a user is disclosed. Themonitor system includes a sensor to produce a signal indicative of aglucose characteristic measured in the user, the sensor further having asensor port. The monitor system further includes a recorder within arecording housing, the recorder hosing also encompassing a batter. Therecorder further includes a recorder port that interfaces with thesensor port in order to receive the produced signals from the sensorport. A recorder clock that assigns a time to the signals from thesensor is also defined within the recorder housing, as is a recorderprocessor that includes a recorder memory that is coupled to therecorder port to store the produced signals from the sensor. Therecorder further includes a data port defined to interface with a dockreceiver. A dock that is remotely located from the sensor and therecorder is also included with the monitor system. The dock includes thedock receiver that physically couples the recorder to the dock via thedata port and a dock processor that is coupled to the dock receiver. Themonitor system further includes a data processor defined to analyze thesignals from the sensor that were stored in the recorder. The dataprocessor includes a data processor memory to store data from therecorder and a data processor clock. Further included with the dataprocessor is a program to assign the time and date of the signals fromthe sensor by comparing the time and date on the data processor clockwith the time assigned to the signals from the sensor by the recorderclock.

Other features and advantages of the invention will become apparent fromthe following detailed description, taken in conjunction with theaccompanying drawings which illustrate, by way of example, variousfeatures of embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A detailed description of embodiments of the invention will be made withreference to the accompanying drawings, wherein like numerals designatecorresponding parts in the several figures.

FIG. 1 is an exemplary illustration of components of a monitor system,in accordance with embodiments of the present invention.

FIG. 2A is an exemplary block diagram illustrating components within arecorder, in accordance with one embodiment of the present invention.

FIGS. 2B-2D illustrate various embodiments of a detail of a recorderport, in accordance with embodiments of the present invention.

FIGS. 3A-3D are schematic illustrations of connecting a dock to wallplug, in accordance with embodiments of the present invention.

FIGS. 4A and 4B are illustration showing the placement of the recorderonto the dock, in accordance with embodiments of the present invention.

FIGS. 5A-5C are exemplary illustrations of placement of a sensor andinstallation of the recorder onto the sensor, in accordance withembodiments of the present invention.

FIG. 6A-6C are exemplary schematics illustrating the removal of therecorder from the sensor and placement of the recorder back onto thedock, in accordance with embodiments of the present invention.

FIG. 6D is an illustration showing a recorder that contains recordedsensor data connected to a dock that is connected to a data processorvia a cable, in accordance with embodiments of the present invention.

FIGS. 7A-7D are a series of illustrations that demonstrate actionablefeedback provided by an icon cluster when the recorder is connected to adock, in accordance with embodiments of the present invention.

FIGS. 8A-8D are larger illustrations of the icon cluster in accordancewith embodiments of the present invention.

DETAILED DESCRIPTION

As shown in the drawings for purposes of illustration, the invention isembodied in a monitor system coupled to a subcutaneous implantableanalyte sensor set to provide continuous data recording of the sensorreadings for a period of time. The recorded data later being downloadedor transferred to a computing device to determine body characteristicdata based on the data recording over the period of time. In embodimentsof the present invention, the analyte sensor set and monitor system arefor determining glucose levels in the blood and/or bodily fluids of theuser without the use of, or necessity of, complicated monitoring systemsthat require user training and interaction. However, it will berecognized that further embodiments of the invention may be used todetermine the levels of other analytes or agents, characteristics orcompositions, such as hormones, cholesterol, medications concentrations,viral loads (e.g., HIV), or the like. In other embodiments, the monitorsystem may also include the capability to be programmed to record dataat specified time intervals. The monitor system and analyte sensor areprimarily adapted for use in subcutaneous human tissue. However, stillfurther embodiments may be placed in other types of tissue, such asmuscle, lymph, organ tissue, veins, arteries or the like, and used inanimal tissue. The analyte sensors may be subcutaneous sensors,transcutaneous sensors, percutaneous sensors, sub-dermal sensors, skinsurface sensors, or the like. Embodiments may record sensor readings onan intermittent or continuous basis.

FIG. 1 is an exemplary illustration of components of a monitor system10, in accordance with embodiments of the present invention. Aperspective view of a dock 100 illustrates icon cluster 106 and a dockreceiver 108 that is configured to connect to a recorder data port 110on the recorder 104. The recorder port 110 of the recorder 104 is alsoconfigured to connect to a sensor port 112 that is included on a sensor102. The illustration of the sensor 102 is an exemplary top view of thesensor 102 after it has been inserted into a patient. In someembodiments, the sensor 102 is an assembly commonly known as a “sensorset” that includes, but it not limited to the sensor port 112, sensoradhesive (not shown) covered by an adhesive backing 116, an introducerneedle (not shown in FIG. 1), a sensing portion to be placed in a body(not shown), and a mounting base. In many embodiments the sensor setutilizes an electrode-type sensor that is used to monitor blood glucoselevels. A data processor 114 is also included in the monitor system 10.In some embodiments the data processor 114 is a general purpose computersuch as a netbook, notebook computer or desktop computer that canconnect to the dock 100. In other embodiments, the data processor 114can be more specialized computing devices such as smartphones or purposebuilt computers. In further embodiments, the data processor includes anInternet connection and employs an Internet-based server and Internetsoftware application.

In some embodiments the recorder 104 is a Holter-type recording devicethat can be interfaced with both the dock 100 and the sensor 102. In oneembodiment the sensor 102 utilizes an electrode-type sensor while inalternative embodiments, the sensor 102 may use other types of sensors,such as chemical based, optical based or the like. In furtheralternative embodiments, the sensor 102 may be of a type that is used onthe external surface of the skin or placed below the skin layer of theuser or placed in the blood stream of the user. Other embodiments of asurface mounted sensor would utilize interstitial fluid harvested fromthe skin.

The recorder 104 generally includes the capability to record and storedata as it is received from the sensor 102, and includes a recorder port110 that can be coupled with either the sensor 102 or the dock 100. Whenthe recorder 104 is coupled to the dock 100 and the dock 100 is incommunication with the data processor 114, data stored on the recorder104 can be transferred to the data processor 114. To enable datatransfer between either the sensor 102 or the dock 100 the recorder 104may include a recorder port 110 that is designed to establishcommunication between the sensor 102 or the dock 100.

Further description regarding the sensor and associated sensor set canbe found in U.S. Pat. No. 6,248,067, entitled ANALYTE SENSOR ANDHOLTER-TYPE MONITOR SYSTEM AND METHOD OF USING THE SAME, U.S. Pat. No.5,586,553, entitled TRANSCUTANEOUS SENSOR INSERTION SET, and U.S. Pat.No. 5,594,643, entitled DISPOSABLE SENSOR INSERTION ASSEMBLY, all ofwhich is herein incorporated by reference.

FIG. 2A is an exemplary block diagram illustrating components within therecorder 104, in accordance with one embodiment of the presentinvention. A power supply 212 connected to power management 214 is foundwithin the housing 202 of the recorder 104. In some embodiments thepower supply 212 is a battery assembly that uses a rechargeable batterychemistry to provide power to recorder 104. In one embodiment the powersupply 212 is made up of lithium ion battery cells. However, it isunderstood that alternate battery chemistries may be used, such asnickel metal hydride, alkaline or the like. Similarly, variousembodiments can use a single battery cell while other embodiments usemultiple battery cells.

The power management 214 includes circuitry and programming to allowrecharging of the power supply 212 via the recorder port 110. In someembodiments power management 214 also includes circuitry and programmingthat enables a low battery warning alarm. In some embodiments the powersupply 212 is capable of enabling the recorder 104 to record data forseven days. Additionally, after seven days of recording, the powersupply further enables operation of an integrated clock in the recorder104 for an additional seven days. Alternative embodiments may providelonger or shorter battery lifetimes, or include a power port or solarcells to permit recharging of the power supply 212.

The sensor 102 is connected via the sensor port 112 and the recorderport 110 to a signal conditioning circuit 200, such as a potentiostat orthe like, in a housing 202 of the recorder 104. The signal conditioningcircuit 200 is in turn connected to a current to frequency converter (Ito F) 204. The output of the current to frequency converter 204 is adigital frequency that varies as a function of the sensor signalproduced by the sensor 102. In alternative embodiments, other signals,such as voltage, or the like, may be converted to frequency. In oneembodiment, the digital frequency is then counted by a digital counter206, and a value from the digital counter 206 is periodically read andstored with an indication of elapsed time, by a microprocessor 208, intoa non-volatile memory 210.

In some embodiments the microprocessor 208 includes an integrated clockthat begins tracking elapsed time when the recorder 104 determines thesensor 102 is properly hydrated. The integrated clock is also used todetermine when events occur such as periodic sample readings from thesensor 102. The periodic readings from the sensor 102 are stored to thememory 210 with an elapsed clock reading from the integrated clock. Inother embodiments, the clock is separate and distinct from themicroprocessor 208 but is still contained within the housing 202. Insuch embodiments, the microprocessor 208 is still programmed andconfigured to initiate the clock when the sensor 102 is properlyhydrated. Additionally, the microprocessor 208 is programmed andconfigured to read and record the elapsed time of the clock. As will bediscussed later, the elapsed clock time from the integrated clock of therecorder 104 can be used to retrospectively determine times of theperiodic readings.

In some embodiments, the recorder 104 provides power to drive the sensor102 via the recorder port 110 and the sensor port 112. Power from therecorder 104 may also be used to speed initialization of the sensor 102,when it is first placed under the skin. The use of an initializationprocedure can result in a sensor 102 providing stabilized data in anhour or less compared to requiring several hours before stabilized datais acquired without using an initializing procedure. One exemplaryinitialization procedure uses a two step process. First, a high voltage(preferably between 1.0-1.2 volts—although other voltages may be used)is applied to the sensor 102 for one to two minutes (although differenttime periods may be used) to initiate stabilization of the sensor 102.Then, a lower voltage (preferably between 0.5-0.6 volts—although othervoltages may be used) is applied for the remainder of the initializationprocedure (typically 58 minutes or less). The initialization proceduredescribed above is exemplary and other initialization procedures usingdiffering currents, voltages, currents and voltages, different numbersof steps, or the like, may be used.

FIGS. 2B-2D illustrate various embodiments of detail 220 of the recorderport 110, in accordance with embodiments of the present invention.Detail 220 shows top contacts 222 and bottom contacts 224 which togethercan simply be referred to as “the recorder contacts”. In the embodimentillustrated the recorder contacts are mounted to a circuit board 226 towhich the components described in FIG. 2A are also mounted. The recordercontacts can be board mounted springs, or simple contact pads, or anyother variety of contact that creates a reliable electrical connection.

The configuration illustrated is intended to be exemplary and should notbe construed to be limiting. For example, in alternative embodimentsshown in FIG. 2C, rather than a single recorder port 110 (FIG. 2A), thesensor 104 could have two separate ports with the first port 250providing access to top contacts 222 while the second port 252 providesaccess to bottom contacts 224. Similarly, other embodiments could usetwo separate ports while placing the bottom contacts 224 on the sameside of the circuit board 226 as the top contacts 222, as shown in FIG.2D.

As illustrated the recorder contacts are protected from damage and/orfouling by being recessed within the recorder data port 110. Inalternative embodiments, the recorder contacts can be exposed on theexterior of the recorder 104 and rely on pins or pads from the both thesensor 102 (FIG. 1) and the dock 100 (FIG. 1) to make electricalcontact. The recorder contacts are used for multiple purposes such as,but not limited to, allowing the power supply 212 (FIG. 2A) within therecorder 104 to provide power to the sensor 102 (FIG. 1), transmittingdata from the sensor 102 (FIG. 1) to memory 210 within the recorder 104,transmitting data stored in the memory 210 (FIG. 2A) of the recorder 104to a data processor 114 (FIG. 1), and recharging the power supply 212(FIG. 2A) of the recorder 104. In some embodiments the top contacts 222are used to record sensor data and deliver power to the sensor 102.Similarly, the bottom contacts 224 are used to charge the power supply212 (FIG. 2A), transfer data from the recorder 104 to the data processor114 and perform diagnostic tests of the recorder components shown inFIG. 2A. The particular examples described above should be considereddemonstrative and should not be construed as limiting the presentinvention. In other embodiments different combinations andconfigurations of recorder contacts may be used to perform variousrecorder functions and features.

FIGS. 3A-3D are schematic illustrations of connecting the dock 100 towall plug 304, in accordance with embodiments of the present invention.FIG. 3A illustrates plugging cable 302 a into a dock port 300 where thedock port 300 is integrated into the dock 100. In some embodiments thedock port 300 is chosen from a variety of standard ports in order tosimplify manufacturing and distribution. As illustrated, the dock port300 is a standard female mini-USB type connector while cable end 302 bis the corresponding standard male mini-USB type connector. Alternateembodiments can use various connectors that are capable of supplyingpower and transmitting data. For example the cable end 302 b could use aproprietary connector and dock port 300 could have a correspondingproprietary socket. Alternatively, a variety of USB connectors andsocket could be used, including, but not limited to Type A, Type B,Micro-AB and Micro-B. FIG. 3B illustrates plugging cable end 302 c intothe wall plug 304. For simplicity of distribution, FIG. 3B shows cableend 302 c as Type A USB plug while a plug receptacle 308 is a USB Type Areceptacle. As described above, various plugs and receptacles can beused in place of those shown in FIG. 3B.

FIG. 3C illustrates a single dock 100 being powered from a power strip310. The wall plug 304 is connected to the power strip 310 and power istransmitted to the dock 100 via the cable 302 a. In one embodiment, thedock 100 includes hardware and software to determine if enough power isbeing supplied to the dock 100. In situations where the dock 100 isreceiving appropriate levels of power the power indicator 306 will beconstantly illuminated. The power indicator 306 is part of the iconcluster 106 which will be discussed in more detail during thedescription of FIGS. 7 and 8.

FIG. 3D is an exemplary illustration showing multiple docks 100 eachdrawing power from the power strip 310 via the wall plugs 304. Theability to supply power to the dock 100 via the wall plug 304 or via aUSB port from a data processor 114 (FIG. 1) allows practitioners to usemultiple docks 100 without requiring multiple data processors. Thisallows a practitioner to have a central location for multiple docks 100separate and distinct from the data processor 114 (FIG. 1). With manypractitioners, data processors 114 (FIG. 1) in their office may belocated near a reception area that is separated from patient exam orconsultation rooms. Thus, depending on placement of data processors in agiven office, the ability to charge recorders 104 (FIG. 1) using docks100 that are simply plugged into a wall may be advantageous as thepractitioner may have limited access to data processors 114 (FIG. 1).

FIGS. 4A and 4B are illustration showing the placement of the sensor 104onto the dock 100, in accordance with embodiments of the presentinvention. As shown in FIG. 1, the dock 100 includes dock receiver 108.The dock receiver 108 (FIG. 1) includes electrical contacts that in oneembodiment, interface with bottom contacts 224 (FIG. 2B). A hood 400 isincluded on the dock 100 in order to protect the electrical contacts onthe dock receiver 108 (FIG. 1). As shown in FIG. 4A, the hood 400extends over the dock receiver 108 (FIG. 1) and protects the dockreceiver 108 (FIG. 1) from being deformed or rendered unable to couplewith the recorder port 110. In the embodiment illustrated in FIG. 4A therecorder 104 is pushed in direction D₁ onto the dock receiver 108(FIG. 1) which results in what is shown in FIG. 4B. Note that the iconcluster 106 remains visible after the recorder 104 is coupled with thedock 100. In some embodiments, an additional cleaning plug (not shown)is used to seal the recorder port 110 to prevent liquids from enteringthe recorder port 110 so the recorder 104 can be cleaned before therecorder 104 is coupled with the dock 100. The additional step ofcleaning the recorder port 110 can reduce or prevent fouling of thedock.

As previously discussed, the dock 100 can draw power from either a wallplug 304 (FIG. 3C) or data processor 114 (FIG. 1). When the dock 100 ofFIG. 4B is connected to sufficient power via a wall plug 304 (FIG. 3C)or via a connection with the data processor 114 as shown in FIG. 6D,hardware and software within the dock 100 will begin charging the powersupply 212 (FIG. 2A) within the recorder 104. As will be discussed inthe description of FIGS. 7 and 8, a battery indicator 402 on the dock100 provides actionable user feedback regarding the state of the powersupply 212 (FIG. 2A) within the recorder 104.

FIGS. 5A-5C are exemplary illustrations of placement of a sensor 102 andinstallation of the recorder 104 onto the sensor 102, in accordance withembodiments of the present invention. FIG. 5A illustrates a sequence oftypical steps used to place the sensor 102 within interstitial fluid ofa patient. The leftmost panel of FIG. 5A is illustrative of using aninserter 500 to assist in the installation or placement of the sensor102. Commonly, inserters 500 are customized to accommodate a specifictype of sensor 102. For additional information regarding inserters 500please see U.S. patent application Ser. No. 10/314,653 filed on Dec. 9,2002, entitled INSERTION DEVICE FOR INSERTION SET AND METHOD OF USINGTHE SAME, U.S. Pat. No. 6,607,509, entitled INSERTION DEVICE FOR ANINSERTION SET AND METHOD OF USING THE SAME, and U.S. Pat. No. 5,851,197entitled INJECTOR FOR A SUBCUTANEOUS INFUSION SET, all of which areherein incorporated by reference.

The middle panel of FIG. 5A is an illustration showing the removal ofthe adhesive backing 116 to expose an adhesive that enables adhesion ofthe sensor 102 to the skin 504 of a patient. The rightmost panel of FIG.5A is an illustration that depicts the removal of an introducer needle506 that is used during the placement of the sensor 102. FIG. 5B is anexemplary illustration showing the installation of the recorder 104 ontothe sensor 102. Direction arrows D₂ indicate that the recorder 104 ispushed onto the sensor 102 that was adhered to the patient, as shown inthe middle panel of FIG. 5A. In some embodiments, it is desirable towait a predetermined period of time before installing the recorder 104onto the sensor 102. For example, it may be advantageous to wait for upto 15 minutes for the sensor 102 to be properly hydrated or wetted bythe patient's interstitial fluid before attaching the recorder 104. Inother embodiments it may take longer before is sensor is consideredproperly hydrated. Being able to detect if an installed sensor 102 isproperly hydrated can be used by a practitioner to help determine if thesensor was properly installed into the interstitial fluid. In otherembodiments there is no minimum time required before attaching therecorder 104 to the sensor 102. In still more embodiments, the sensor102 need not be hydrated before the recorder 104 is connected. And inadditional embodiments, the recorder may be integrated with the sensorbefore the sensor is inserted into a user.

As illustrated in FIG. 5C, some embodiments of the recorder 104 includea feedback indicator 502. In one embodiment the feedback indicator 502is a Light Emitting Diode (LED) that can be seen through a translucentor semi-translucent housing. In other embodiments, different lightelements can be used, such as, but not limited to incandescent lights,fluorescent lights, Organic Light Emitting Diodes (OLED) or the like. Instill other embodiments, the feedback indicator can be an audible toneor a vibration alarm similar to those in mobile phones. In embodimentswith the feedback indicator, the recorder 104 can provide feedbackregarding the hydration level of a connected sensor. For example, therecorder includes hardware and software that can determine if the sensor102 is properly hydrated. The feedback indicator 502 can help apractitioner by narrowing the type of troubleshooting that needs to beperformed. For example, the feedback indicator 502 can be programmed toflash a specific sequence or color to indicate that the sensor 102 isproperly hydrated. Similarly, the feedback indicator 502 can beprogrammed to flash a different sequence or color to indicate that thesensor is not properly hydrated. In other embodiments, the feedbackindicator 502 can further be programmed to flash a particular sequenceor color that indicates to a practitioner that the sensor 104 is notfully charged or even that data needs to be transferred from therecorder 104 before additional data can be recorded. The examplesprovided are not intended to be exhaustive of conditions that can bereported by the feedback indicator 502. The particular examples providedare intended to be exemplary and should not be construed as limiting thescope of the present invention.

In some embodiments, the recorder 104 detects the connection of thesensor 102 and activates the recorder 104 for a specified monitoringperiod where sensor data is recorded onto the recorder 104, such as 3days, 4 days, 5 days, 6 days, 7 days, or more. In some embodiments, therecorder 104 will stop recording data after the specified monitoringperiod. In specific embodiments, the practitioner can program therecorder with a predefined duration that the recorder will operatebefore it stops collecting sensor data. In particular embodiments therecorder 104 will set an internal “study complete” flag when it stopscollecting sensor data and the recorder 104 will not collect more sensordata until the “study complete” flag is removed. In some embodiments the“study complete” flag is removed when the sensor data in the recorder104 is cleared from the recorder memory, such as by uploading the sensordata to the data processor 114 or by clearing the sensor data withoutdownloading the sensor data first. In particular embodiments, therecorder 104 includes hardware and software to detect when a properlyhydrated sensor is connected for the first time and begins to initializethe sensor 102. Additionally, the recorder 104 can set a “study inprocess” flag, an internal flag such as a bit or switch, so the recorder104 will not perform an initialization sequence again until aftersubsequently recorded data is retrieved or downloaded from the recorder104. Thus, if the sensor 102 is pulled out of the interstitial fluid ofa patient, hardware and software within the recorder 104 will detect achange in capacitance measured across two or more sensor electrodes andset a “discard flag” so that all data recorded while the sensor ispulled out and be identified and ignored. Should the sensor be pushedback into the interstitial fluid of the patient, the recorder 104 isable to detect when the sensor 102 is rehydrated by the change incapacitance. Once a rehydrated sensor is detected, the recorder 104 willrecognize that the “study in process” flag is set and will notreinitialize the sensor 102. Rather, when a rehydrated sensor isdetected, the recorder 104 will remove the discard flag.

In alternative embodiments the recorder 104 will wait a pre-determinedperiod of time for the sensor signal to stabilize before removing thediscard flag. The “study in process” flag is removed when the sensordata is cleared from the recorder's memory such as by uploading the datato the data processor 114 or clearing the recorder's memory withoutuploading data. In some embodiments the pre-determined period of time towait for sensor signal stabilization is approximately 30 minutes. Inother embodiments, additional or less time can be afforded to sensorsignal stabilization. Sensor life is improved by not re-initializing thesensor 102 after the sensor is rehydrated and furthermore, power drawfrom the recorder power supply 212 (FIG. 2A) is minimized. In otherembodiments, the recorder 104 can determine if sensor data has beencollected, and if sensor data is stored in the recorder's memory, thenthe recorder 104 will not reinitialize when a rehydrated sensor isdetected. The recorder will initialize a sensor only after the sensordata has been cleared from the recorder's memory. For additionalinformation regarding initialization and stabilization of a sensorplease see U.S. patent application Ser. No. 12/345,354 filed on Dec. 29,2008 entitled METHOD AND SYSTEMS FOR OBSERVING SENSOR PARAMETERS whichis herein incorporated by reference.

In one embodiment, the recorder 104 is programmed to record periodicsensor data for seven days, as timed by the recorder's internal clock.In one embodiment, the internal clock within the recorder is used todetermine the periodic intervals for recording sensor data. Thus, aftera predetermined period of time has elapsed after being connected to ahydrated sensor, data from the sensor is recorded with an associatedtime stamp from the internal clock. For example, if the recorder isprogrammed to record sensor data every 30 minutes after being connectedto a properly hydrated sensor, the first record of sensor data will betime stamped as occurring after 30 minutes. After recording seven daysof sensor data the power supply 112 will still have sufficient power tokeep the internal clock running for an additional seven to 11 days. Inother embodiments, the recorder 104 will supply power for more than 11days after the sensor data is recorded. The additional seven to 11 daysafter recording of sensor data has ceased provides enough time for apatient to return to a practitioner's office to return the recorder 104and give the practitioner time to download or retrieve the stored sensordata from the recorder 104. To retrieve stored sensor data the recorder104 is placed into a dock 100 that is connected to a data processor 114(FIG. 1).

FIG. 6A-6C are exemplary schematics illustrating the removal of therecorder 104 from the sensor 102 and placement of the recorder 104 backonto the dock 100, in accordance with embodiments of the presentinvention. FIGS. 6A and 6B are illustrative of a two step procedure toremove the recorder 104 from the sensor 102. As shown in FIG. 6A apractitioner or the patient squeezes the sensor 102 in the direction D₃in order to release clips or snaps that help connect the recorder 104 tothe sensor 102. Subsequently, the recorder 104 is moved in the directionD₄ to remove or uncouple the recorder 104 from the sensor 102. After therecorder 104 is removed from the sensor 102, the sensor can be removedfrom the patient and the recorder 104 can be cleaned using thepreviously discussed cleaning plug before placing the recorder 104 on adock 100 as shown in FIG. 6C.

FIG. 6D is an illustration showing a recorder 104 that contains recordedsensor data connected to a dock 100 that is connected to a dataprocessor 114 via cable 302 a, in accordance with embodiments of thepresent invention. A recorder 104 that contains recorded sensor data canbe recharged using a dock 100 connected to a wall outlet, however asdiscussed above, the recorder 104 will have set an internal “study inprocess” flag that prevents the recorder 104 from performing anadditional initialization sequence until the recorded data is retrievedor downloaded from the recorder 104. Thus, it is preferable forrecorders 104 with recorded sensor data to be placed on a dock 100 thatis connected to a data processor 114. In other embodiments, the recorder104 will set the “study complete” flag when if the recorder 104 containssensor data and is connected to the dock 100. Thus, the recorder 104will collect no additional data until the sensor data in the recorder iscleared, not even if the recorder is reconnected to a hydrated sensor.This helps to minimize the possibility of the recorder 104 containingdata from a first patient and then being placed on a second patientbefore the data is cleared from the first patient. Furthermore, therecorder LED 502 will not flash when connected to a hydrated sensor ifthe “study complete” flag or the “study in process” flag is set. Thistells the practitioner that the recorder 104 is not initializing thesensor.

When the dock 100 is connected to a data processor 114 and the recorder104 is connected to the dock, 100, stored sensor data can be downloadedfrom the recorder 104 to the data processor 114. As previouslydiscussed, the stored sensor data includes time stamps regarding whenthe sensor data was recorded relative to the internal clock of therecorder 104. The time stamped recorded data can be used in conjunctionwith a clock associated with the data processor 114 to retrospectivelydetermine the actual time data was recorded.

In one embodiment of the present invention, the recorder's internalclock does not stop when the recorder 104 is removed from the sensor102. Then the recorder 104 is connected to the dock 100 and the dock 100is connected to the data processor 114 such as by using cable 302 a, therecorder can download sensor data to the data processor 114. Therecorder 104 provides sensor data that is time stamped with the age ofthe sensor readings. So, the data processor 114 can refer to a clockassociated with the data processor 114 to determine the time and datewhen the sensor data is downloaded from the recorder 104. Then the dataprocessor 114 can compare the age of the last sensor reading to the timeand date when the download occurred to determine the time and date thatthe sensor data was recorded. This can be done with each sensor reading.

This process of retrospective time stamping can better be appreciatedthrough the following example. In this example when sensor data wasdownloaded from the recorder 114 to the data processor 114 the clockassociated with the data processor indicated 1:00:00 pm on Monday, Thedownloaded sensor data included the age of each sensor reading. The lastsensor reading occurred 4 hours before the sensor data was downloaded tothe data processor 114. The data processor 114 subtracts 4 hours fromthe time and date that the download occurred to determine that the lastsensor reading was recorded at 9 AM on Monday morning. The time and dateof each sensor reading is calculated similarly.

In an alternative embodiment, the recorder 104 is coupled with a dock100 that is connected to a data processor 114, the internal clock of therecorder 104 is stopped. In this example, the internal clock of therecorder is stopped at 10 days, 5 hours 15 minutes and 30 seconds. Thismeans the recorder 104 detected a properly hydrated sensor 10 days, 5hours, 15 minutes and 30 seconds ago. Additionally, 72 hours has elapsedon the internal clock since the last sensor data reading was recordedand the clock of the data processor 114 is reading 3 PM on Apr. 16,2010. Thus, based on the present time and date reported by the dataprocessor 114 and the elapsed time of the internal clock of the recorder104, it can be determined that the last sensor reading was taken on Apr.13, 2010 at 3 PM. As all recorded sensor data includes a time stampbased on the elapsed time of the internal clock, similar retrospectivecalculations can be used to determine actual time based on the timereported by the data processor 114 for the other recorded sensor data.

In still other embodiments, a Blood Glucose Meter (BGM) or otherreference device could be used in conjunction with the sensor andmonitor system 10 (FIG. 1) to assist with calibration of sensor data. Inone embodiment BGM data is downloaded from the BGM to the data processor114 and retrospectively time stamped or calibrated similar to the sensordata. Thus, a practitioner will not need to set the proper time and dateon the meter before the study. If the time and date of the BGM isincorrect, the data processor 114 can compensate by comparing the timeand date of the data processor 114 to the incorrect time of the BMG. Thedata processor has access to the time and data of the BGM when BGM datais being downloaded from the BGM to the data processor 114. The dataprocessor 114 can apply the difference between the time and date asreported by the BGM and the time and date of the data processor 114 todetermine the correct time and date for each BGM reading.

While FIG. 6D and the above description describe data transfer betweenthe recorder 104 and the data processor 114 via the cable 302 a, otherembodiments allow the dock 100 to draw power through cable 302 a whiledata transfer is conducted using wireless communications such as, butnot limited to Wi-Fi, Bluetooth, ultrasonic frequencies, infrared or thelike. Additionally, alternate embodiments of the dock 100 do not requirethe cable 302 a to transfer power as the dock can include inductivepower capabilities or the dock includes an internal power supply such asa battery.

FIGS. 7A-7D are a series of illustrations that demonstrate actionablefeedback provided by the icon cluster 106 when the recorder 104 isconnected to a dock 100, in accordance with embodiments of the presentinvention. While the FIG. 7A shows the dock 100 connected to a dataprocessor 114 the dock can include hardware and software that enablesthe dock 100 to perform the functions described below while beingconnected to a wall plug 304 (FIG. 3B). FIG. 7B is an exemplaryillustration showing the state of icon cluster 106 as the recorder 104is coupled to the dock 100. Note that power indicator 306 is illustratedas being steadily illuminated while the battery indicator 402 and awarning indicator 700 are not illuminated or flashing. This condition isindicative that the dock 100 is receiving sufficient power from the dataprocessor 114 and the dock 100 has not begun an initializationprocedure. In FIG. 7C the recorder 104 has been coupled to the dock 100and every element within the icon cluster 106, the power indicator 306,the battery indicator 402 and the warning indicator 700 are flashing.This condition indicates that the dock 100 is performing aninitialization in response to the recorder 104 being coupled to the dock100. In one embodiment, if there is sufficient power, the powerindicator remains illuminated while the battery indicator and warningindicator are turned off. Using a standard USB cable 302 a to supplypower to the dock 100 exposes the dock 100 to power inconsistencies fromdata processor 114 USB ports. Though the USB specification details thepower requirement that are required from a USB port, various factorsincluding, but not limited to, cable length, wire gauge within thecable, and the number of devices attached to the bus can affect theactual power supplied to a device.

Notification that the dock 100 is receiving sufficient power is providedto a user by illuminating the power indicator 306, which in oneembodiment is a white LED. Thus, when the dock 100 is initialized byeither being plugged in or upon detecting the presence of a recorder 104and the power indicator 306 is not constantly illuminated, it isindicative that the dock 100 is not receiving sufficient power. Torectify the lack of power the user can be instructed to use a poweredUSB hub, or to try a different USB cable. In embodiments where the dock100 includes a power indicator and associated hardware and/or softwareactionable feedback regarding the power supply to the dock 100 can beprovided to the user. Without the actionable feedback provided by thepower indicator 100 it could be more difficult to troubleshoot issueswith both the dock 100 and the recorder 104.

FIG. 7D is an illustration where the power indicator 306 is shown asilluminated while the battery indicator 402 is shown as flashing, inaccordance with embodiments of the present invention. A flashing batteryindicator 402 can be indicative of two conditions that can occur whenthe dock 100 is connected to either a wall plug 304 (FIG. 3B) or a dataprocessor 114. A flashing battery indicator 402 provides actionablefeedback by indicating that the battery within the recorder 104 is beingrecharged or that the recorder 104 contains recorded sensor data thathas not been downloaded to a data processor 114. When the batteryindicator 402 becomes steadily illuminated it is indicative that thebattery within the recorder 104 is completely charged. However, if arecorder 104 has stored sensor data the battery indicator 402 willcontinue to blink even after the battery has been charged. This cannotify a practitioner that the recorder 104 needs to be connected to adock 100 that is connected to a data processor 114 so the stored sensordata can be transferred off of the recorder 104.

As previously discussed, it is only after stored sensor data istransferred or downloaded from the recorder 104 to the data processor114, that the recorder 104 can be used to record additional sensor data.Thus, it should be apparent to a practitioner that a prolonged flashingbattery indicator 402 of a dock 100 may be indicative of a recorder 104that is not available for use. In one embodiment, the battery indicatoris a green LED that can be programmed to flash different sequences todistinguish between a dock 100 that is charging a recorder 104 and adock 100 that has a recorder 104 containing sensor data. In alternativeembodiments, the dock includes an indicator to show the status of thebattery within the recorder 104 and a separate indicator to show thestatus of data stored on the recorder 104.

As mentioned above, the icon cluster 106 also includes a warningindicator 700. This allows the dock 100 to provide actionable feedbackregarding the operational readiness of a recorder 104. In addition toproviding feedback via the power indicator 306 and the battery indicator402, the dock 100 includes hardware and software that is able to performdiagnostic testing of a recorder 104 connected to the dock 100. Theresults of the diagnostic test can be provided as feedback to a user viathe warning indicator 700. As previously discussed, the dock 100includes dock receiver 108 (FIG. 1) that couples with the recorder 104to recharge the recorder power supply 212, transfer data from therecorder 104, and perform diagnostic tests of electronic components ofthe recorder 104. As discussed above the recorder 104 includes a memory210 and a processor 208. In some embodiments, the dock 100 is programmedto perform a diagnostic test of communication between the memory 210 andthe processor 208. In other embodiments, the dock 100 performs a test tocheck the integrity of the memory 210. In still other embodiments, thedock 100 performs tests of the recorder power supply 212. In still otherembodiments, the dock 100 verifies that the recorder 104 can communicatewith the dock 100 therefore verifying that the recorder's microprocessor208 is functioning properly and verifying that the connectors 224 in therecorder 104 are not damaged.

While specific types of diagnostic tests have been described above, thetypes of tests should not be construed as limiting. In other embodimentsthe dock 100 can be programmed to perform any number of tests onlylimited by hardware access and programmers inventiveness. A failure ofany of the diagnostic tests performed by the dock 100 results in thewarning indicator flashing at periodic intervals. Alternatively, thewarning indicator can be constantly illuminated if there is a failure ofany of the diagnostic tests. In still another embodiment, in order toreduce troubleshooting the warning indicator can flash in specificsequences to indicate which diagnostic test was failed. In particularembodiments, the warning indicator will turn on if the recorder's powersupply 212 is too low or is taking too long to charge. In otherembodiments, the warning indicator will turn on if the sensor connectors220 are damaged or if the electronics in the recorder 104 used tooperate the sensor are not functioning properly. To convey theseriousness of a failed diagnostic test, in some embodiments the warningindicator 700 is a red LED.

FIGS. 8A-8D are larger illustrations of icon cluster 106 in accordancewith embodiments of the present invention. FIG. 8A is an example of theicon cluster 106 where the power indicator 306, the battery indicator402 and the warning indicator 700 are flashing during initialization ofthe dock 100. FIG. 8B is an example of the icon cluster 106 when thepower indicator 306 is steadily illuminated while the battery indicator402 and the warning indicator 700 are not illuminated or flashing. Thisprovides feedback to a user by indicating that sufficient power beingsupplied to the dock 100 and the recorder 104 is not connected to thedock 100. FIG. 8C is an example of the icon cluster 106 when the powerindicator 306 is steadily illuminated, the battery indicator 402 isflashing, and the warning indicator 700 is not illuminated nor flashing.This feedback indicates to a user that the dock 100 is receivingsufficient power and either the recorder's power supply 212 is chargingor that the recorder 104 contains recorded sensor data that has not beendownloaded. FIG. 8D is an example of the icon cluster where the powerindicator 306 is steadily illuminated, the battery indicator 402 issteadily illuminated, and the warning indicator 700 is not illuminatednor flashing. Such exemplary feedback is indicative that the recorder104 in the dock 100 is fully charged and is ready to be connected to asensor.

The icon cluster is used to provide actionable feedback to a user withthe intent of minimizing difficulty when troubleshooting the systemwhile ensuring integrity of data stored on the recorder 104. The use ofthree different colored LEDs for the power indicator 306, the batteryindicator 402 and the warning indicator 700 should not be construed aslimiting as a single multicolored LED may be used or combinations ofvarious lighting types. Additionally, the use of only visual feedbackshould not be construed as limiting. Other embodiments of the dock 100can include both visual feedback as discussed above along with audiblefeedback of various frequencies and rhythms.

While the description above refers to particular embodiments of thepresent invention, it will be understood that many modifications may bemade without departing from the spirit thereof. The accompanying claimsare intended to cover such modifications as would fall within the truescope and spirit of the present invention.

The presently disclosed embodiments are therefore to be considered inall respects as illustrative and not restrictive, the scope of theinvention being indicated by the appended claims, rather than theforegoing description, and all changes which come within the meaning andrange of equivalency of the claims are therefore intended to be embracedtherein.

What is claimed is:
 1. A monitor system to monitor a characteristic of auser, the system comprising: a sensor to produce a sensor signal on acontinuous basis, the sensor signal being indicative of a glucosecharacteristic measured in the user when placed in subcutaneous tissue,the sensor having a sensor port; a recorder that includes a recorderhousing, a battery being contained within the recorder housing, arecorder port defined to interface with the sensor port to receive theproduced signals from the sensor, a recorder clock defined within therecorder housing to assign a time to the signals from the sensor, arecorder processor that includes a recorder memory coupled to therecorder port to store the produced signals from the sensor, a data portdefined to interface with a dock receiver, a dock remotely located fromthe sensor and the recorder, the dock includes the dock receiver tophysically couple the recorder to the dock via the data port, a dockprocessor coupled to the dock receiver, and a data processor defined toanalyze the signals from the sensor that were stored in the recorder,the data processor includes: a data processor memory to store data fromthe recorder and a data processor clock, wherein the data processor isprogrammed to assign the time and date of the signals from the sensor bycomparing the time and date on the data processor clock with the timeassigned to the signals from the sensor by the recorder clock, whereinthe sensor port and the data port are combined into one multifunctionport.
 2. A monitor system according to claim 1, wherein the dataprocessor is further programmed to convert the signals from the sensorto glucose concentration values experienced by the user.
 3. A monitorsystem according to claim 1, further comprising: a meter having aninternal meter clock to provide reference values to the data processor,the reference values including a timestamp from the internal meterclock, and the data processor includes a program to assign time and dateto the reference values by comparing the time and date on the processorclock with the timestamp of the reference values from the meter.
 4. Amonitor system according to claim 1, wherein the dock further includes adock port.
 5. A monitor system according to claim 4, wherein the dataprocessor further includes a data processor port.
 6. A monitor systemaccording to claim 5, further comprising a cable defined to interfacebetween the dock port and the data processor port.
 7. A monitor systemaccording to claim 1, such that when the recorder is coupled to thedock, the dock is programmed to: (a) recharge the battery of therecorder, (b) perform a diagnostic test of the recorder, and (c) provideactionable feedback based on results of the diagnostic test.
 8. Amonitor system according to claim 7, wherein the actionable feedback isprovided using at least one light integrated into the dock.
 9. A monitorsystem according to claim 7, wherein the actionable feedback is providedusing audible tones.
 10. A monitor system according to claim 8, whereina first light condition indicates that the recorder is charging or thereare no stored signals from the sensor on the recorder.
 11. A monitorsystem according to claim 7, wherein the diagnostic test includes a testof the recorder processor and the recorder memory.
 12. A monitor systemaccording to claim 8, wherein a second light condition indicates a statewhere the recorder has passed the diagnostic test, the recorder ischarged and the recorder contains no stored signals from the sensor. 13.A monitor system according to claim 7, wherein the actionable feedbackincludes notification when the recorder fails the diagnostic test.
 14. Amonitor system according to claim 1, wherein the recorder furtherincludes feedback indicator.
 15. A monitor system according to claim 14,wherein the feedback indicator is a light that periodically illuminatesto indicate proper hydration of the sensor and establishment ofcommunication between the sensor and recorder.
 16. A monitor systemaccording to claim 1, wherein the recorder provides power to initializethe sensor.
 17. A monitor system according to claim 16, wherein therecorder clock begins running when the sensor is initialized.
 18. Amonitor system according to claim 17, wherein the recorder automaticallystops recording sensor data after the recorder clock has been runningfor a predefined duration.
 19. A monitor system according to claim 18wherein the recorder clock continues to run after the recorder stopsrecording sensor data.